You might also look at senior dogs in breed rescue. They tend to come to us when owners die or go into nursing homes, and they're often used to a life as a beloved indoor companion -- I've known a few who walked into a foster home, stepped up onto the sofa, crossed their paws and seemed to say, "This is my usual spot." When they've been fostered with a family, you tend to get lots of useful information about personalities and quirks.
The reason I mention this option is that there are so few adopters willing to consider these older dogs in rescue. They tend to sit in foster homes a long time, even though they're often the best-behaved, easiest dogs in the rescue.